Answer:
The correct answer is B.. The enzyme is like a lock, and the substrate is like a key.
Enzymes are bioctalyst which accelerate the bio-chemical reactions taking place inside the living organisms.
Enzymes have specific region in their structure for the binding of their substrate which is called as active site. The shape of the active site of the enzyme complements the shape of the substrate.
The shape and amino acid residues of the active site provide the specificity to the enzyme for its substrate.
It can be easily explained with the help of lock and key model in which a substrate (key) perfectly docks in the active site (key hole) of the enzyme (the lock).
Answer: The correct answer is : D. sagittal suture
Explanation: The sagittal suture connects the two parietal bones of the skull, it is a type of synartrotic fibrous joint. Fibrous joints with very little or no mobility are called synartrotic, the bones are held together by fibrous connective tissues. Synarthrosis occurs where there is bone growth. Synarthrosis protects and supports ligaments and muscles.
I am not sure what is the answer
Keystone species ; this is a species whose presence is critical to the composition and integrity of the community